In the proposed work, the electrophysiologic and morphologic properties of the mammalian and amphibian lenses will be investigated. Glass micro-electrodes will be placed in the lens, one for passing current and one for recording the voltage change induced across lens resistive elements by the current flow. Systems analysis techniques will be applied to the data in order to obtain an equivalent electrical model for lens tissue. From the model, membrane resistance, cytoplasmic resistivity and cell-to-cell junctional resistivity will be determined. Stereologic principles will be used to quantitatively determine appropriate morphologic parameters. Changes in both the electrical and morphologic parameters will be sought during experimental cataract formation. BIBLIOGRAPHIC REFERENCES: Rae, J.L., The Electrophysiology of the Crystalline Lens. In Current Topics in Eye Research, Academic Press, 1977, In Press. Eisenberg, R.S., Mathias, R.T., and Rae J.L., Measurement Modeling, and Analysis of the Linear Electrical Properties of Cells. New York Academy of Sciences, 1977, In Press.